Fluorescence Optical Diffusion Tomography

Introduction Optical diffusion tomography #ODT# is emerging as a powerful tissue imaging modality. 1,2 In ODT, images are comprised of the spatially dependent absorption and scattering properties of the tissue. Boundary measurements from several sources and detectors are used to recover the unknown parameters from a scattering model described by a partial differential equation. Contrast between the properties of diseased and healthy tissue might then be used in clinical diagnosis. In principle, sinusoidally modulated, continuous-wave #cw#, or pulsed excitation light is launched into the biological tissue, where it undergoes multiple scattering and absorption before exiting. One can use the measured intensity and phase #or delay# information to reconstruct threedimensional #3-D# maps of the absorption and scattering properties by optimizing a fit to diffusion model computations. As a result of the nonlinear dependence of the diffusion equation photon flux on the unknown parameters